The correct answer is option 4: 1, 2 and 3. The year 1916 holds significance in Indian history because all three options mentioned played important roles during that time.

Option 1 states the Lucknow Session of the Congress. The Lucknow Session, held in 1916, was a crucial event that brought about the reunification of the moderates and extremists factions within the Indian National Congress. This unity was significant in the struggle for India`s independence from British rule.

Option 2 mentions the Congress-League Pact. This pact, also known as the Lucknow Pact, was signed in 1916 between the Indian National Congress and the All India Muslim League. It aimed to foster Hindu-Muslim unity and work together for the common goal of self-government in India.

Option 3 refers to the formation of the Home Rule League. In 1916, Annie Besant and Bal Gangadhar Tilak established the Home Rule League in order to demand self-government for India. It played a major role in mobilizing public support and raising awareness about India`s struggle for independence.

Therefore, all three options were significant events in 1916 and are important milestones in Indian history.